1.Field of the Invention
The present invention relates to a vehicle component for a vehicle, in particular a rail vehicle for high-speed traffic, comprising a surface which, during operation, is exposed to a relative wind-induced air flow having a local main flow direction, wherein the surface has a separation region in which the air flow separates from the surface, and at least one perturbing element associated to the separation region is provided, which is formed in order to introduce a perturbation into the air flow. The invention furthermore relates to a vehicle comprising such a vehicle component.
2.Description of Related Art.
With modern rail vehicles having comparatively high rated operating speeds, the problem generally arises that considerable noise emissions take place, specifically at high speeds, at particular positions on the vehicle where the flow separates from the vehicle components arranged there. This is due, inter alia, to the fact that a continuously widening shear layer is created downstream of the separation point. Periodic formation of pronounced vortices (so-called Kelvin-Helmholtz instability), and the associated sound emission, generally take place in this shear layer.
Such flow separation, with the described effects, occurs on a plurality of different components of the vehicle. For example, the described sound emission naturally takes place particularly at components protruding from the vehicle, for example a pantograph or the like. Likewise, however, regions of the wagon body, the running gear or other attached components (such as roof containers etc.) are also subject to this effect.
In connection with the flow separating at the leading end of a running gear cutout, the document EP 2 106 983 A2 proposes the provision of turbulators in the region of the flow separation edge, these being distributed in the transverse direction of the vehicle and intended to introduce a plurality of smaller turbulences into the shear layer, in order to suppress at least substantially the periodic formation of the above-described vortices. The turbulators may in this case be formed both by a highly roughened surface and by comparatively highly pronounced crenelated projections in the outer skin of the wagon body, which are oriented in the longitudinal direction of the vehicle and therefore in the direction of the local main flow direction. The crenelated projections may themselves in turn be formed by prismatic elements fitted onto the outer skin or corresponding notches in the outer skin of the wagon body.
Although the primarily described configuration with the notches in the outer skin of the wagon body makes it possible to reduce the formation of periodic vortices and the associated noise emission, by a certain increase in the turbulence in the shear layer, it nevertheless entails the disadvantage that the shear layer widens comparatively rapidly, or strongly, in the height direction of the vehicle, so that on the one hand there is a comparatively large impact area of the shear layer on following vehicle components (such as the running gear or into the following bounding wall of the running gear cutout) with the associated sound emission, which is to this extent increased. On the other hand, naturally, such a strongly widened shear layer considerably increases the flow resistance of the relevant vehicle components, and therefore of the overall vehicle.